Descriptive studies - incidence and mortality (00350)Evaluation of demographic, temporal, and geographic variation in cancer rates may suggest clues to the roles of environmental or cultural influences; identification of population subgroups or regions at notably high or low risk may indicate areas where more intensive studies might be particularly fruitful. Cancer incidence and mortality rates also may be used to assess consistency with hypotheses regarding cancer etiology suggested by other scientific studies. We have used incidence data from the Surveillance, Epidemiology, and End Results (SEER) program to investigate demographic patterns. Colorectal cancer incidence rates have declined since the mid-1980s, more rapidly among whites than blacks; and recent rates for proximal and transverse colon cancer were higher among blacks than whites, in contrast to higher rectal cancer rates among whites. These emerging racial disparities probably reflect complicated racial differences between screening practice patterns and etiologic factors. The incorrect classification of hilar cholangiocarcinomas (Klatskin tumors) as intrahepatic cholangiocarcinoma (IC) resulted in an overestimation of IC incidence by 13% and underestimation of extrahepatic cholangiocarcinoma incidence by 15%; even after the exclusion of tumors coded to Klatskin, IC incidence increased at 4% per year during 1992-2000. Patients with Merkel cell carcinoma (MCC), an aggressive neuroendocrine tumor of the skin, were found to be at excess risk of a second primary cancer, especially of the lymphohematopoietic types, both before and after diagnosis of the MCC, suggesting that MCC may share etiologic influences with other malignancies. An analysis of 26,758 cases of soft tissue sarcomas regardless of primary site diagnosed during 1978-2001 found that almost half (47.9%) arose in the soft tissues, 14.0% in the skin, and 7.0% in the uterus; rates varied markedly by race, gender, age, and histologic type, suggesting that these tumors may be etiologically distinct. Correction for hysterectomy prevalence increased endometrial carcinoma incidence rates 95.3% among blacks, 57.6% among Hispanics, and 65.1% in white non-Hispanics, reducing the white non-Hispanic:black rate ratio from 2.27 to 1.93. We are examining mortality following a diagnosis of second primary cancer among 29,356 men with testicular cancer compared to matched cases with de novo cancers. A comprehensive analysis of 114,548 lymphoid neoplasms diagnosed during 1992-2001 classified according to the 2001 World Health Organization (WHO) lymphoma classification revealed that, although whites had the highest incidence for most lymphoid neoplasm subtypes, especially for hairy cell leukemia and follicular lymphoma, rates for plasma cell and T-cell neoplasms were highest among blacks; rates among Asians were considerably lower than among whites or blacks for chronic lymphocytic leukemia/small lymphocytic lymphoma and Hodgkin lymphoma. During 1975-2001, ocular non-Hodgkin lymphoma (NHL) incidence rates rose rapidly at 6.2% and 6.5% per year among white males and females, respectively, and differed little by sex, in contrast to rates for other NHLs that peaked in recent years and occurr predominantly among males. An investigation of 4,310 cases of primary cutaneous lymphoma that sought to apply the WHO- European Organization for Research and Treatment of Cancer new classification system for these cancers found that 76.9% and 22.7% of the SEER cases were of T-cell and B-cell origin, respectively; findings were compared those from the Dutch and Austrian Cutaneous Lymphoma Group. Cancer survivors, including those with lymphoproliferative malignancies, were found to not be at increased risk of amyotrophic lateral sclerosis mortality. Trends in cancer risk among people with AIDS in the United States were assessed by linking data from AIDS and cancer registries.